The Dutch Fe-Migration Mending Test : Exploring Further Areas of Use

Résumé En

The conservation of manuscripts and paper-based objects containing iron gall ink raises specific problems, even when the paper is in good condition. Iron gall inks are sensitive to water and some restoration treatments involving water cause small migrations of ink around the line. These brown halos, generally very subtle, are often acceptable. However, they are accompanied by iron migration that can be detrimental for the conservation of the support. Documents in good condition can be potentially damaged by inappropriate restoration treatments. This problem is all the more crucial as solubility tests performed by paper conservators are unreliable and do not allow identification of migrating compounds. An alternative tool has recently been proposed for treatment. It aims to test the act of treatment itself, which is applied to a paper impregnated with bathophenathroline and stamped with an iron gall ink. Migrations of Fe(II) out of the ink line are visually assessed through the occurrence of pink halos. This test is particularly sensitive. If no pink halo appears, the treatment process can be implemented with confidence on original objects. As this test ensures a satisfactory procedure when repairing originals, it is tempting to use it more generally for any solventbased treatment. To this end, several treatments were evaluated with this test and the results compared with the examination of original manuscripts subjected to the same treatments. This approachshowed that this test is poorly reliable to evaluate alcoholbased treatments as bathophenantroline and its derivatives are alcohol soluble. Regarding water-based treatments, the test is not suitable for assessing immersion treatments but gave convincing results when evaluating treatments using a moderate addition of water and where there is no possible extraction of soluble components. In particular, it allowed the determination of safe humidity levels to be applied.